Lake Maxinkuckee, Physical and Biological Survey 291 



FOOD AND PARASITES OF THE FISHES 



BY CHAELES BRANCH WILSON 



INTRODUCTION 



The paper herewith presented is one of those resulting from 

 an investigation of the animal and plant life found in Lake Max- 

 inkuckee and neighboring waters. The author was sent to the 

 lake in the summer of 1906, and directed to study the parasites 

 and diseases affecting the fishes of the region. 



Mr. H. Walton Clark assisted the writer during his stay at the 

 lake in 1906, and, at various times thereafter, collected and sent 

 to him additional material which has been useful in the study of 

 the food and the external parasites of the fishes of this lake. 



Unfortunately no record could be found of such a study of a 

 limited area of fresh-water, where the entire ground could be 

 covered. Consequently there has been no precedent to serve for 

 guidance and much of the work has been preparatory rather than 

 conclusive. 



The fishes studied were mostly the game and food fishes caught 

 by local and visiting sportsmen, and hence just the ones most de- 

 sirable. Young fish of the same species and others too small or 

 otherwise unfit for food were caught with a seine. 



In this way nearly 1,500 fish, adults and young, were examined 

 during July, August, and the first week in September, and care- 

 ful records were kept of the food and parasites observed. 



It was soon realized that any intelligent discussion of the para- 

 sites must include their life histories and also a careful study of 

 their habits, their enemies, and the physical conditions which 

 might prove advantageous or detrimental to their growth. 



For the three genera of parasitic copepods these data were 

 all obtained, in the case of two of them for the first time; for the 

 various genera of cestodes, trematodes, and Acanthocephali, the 

 data have been already published by Dr. Edwin Linton in his vari- 

 ous excellent papers- dealing with the internal parasites of fresh- 

 water fishes. But for the leeches, which bid fair to prove the most 

 important of the parasites, only a crude beginning could be made. 

 Their importance was not realized until late in the season; only 

 a little time could then be given to them, and they are not a group 

 that can be easily handled. 



The lake was found to be exceedingly well balanced in both its 

 animal and vegetable life, and the fish proved to be disappoint- 



